Power cables embedded in soil or exposed to moisture-rich environments are pointed out as problems to be aged by water treeing due to exterior moisture, ions, etc., and be thus shortened in lifespan. Insulators in which water treeing occurs are deteriorated in electrical insulation property, thus shortening lifespan of cables.
Since accidents often occur due to water treeing, a variety of methods for improving resistance against creation and growth of water trees have been suggested. Korean Patent No. 0561272 discloses prevention of water treeing using a glycidyl methacrylate-grafted copolymer and Japanese Patent Publication Hei 10-64339 and Japanese Patent Publication Sho 63-150811 disclose inhibition on generation and growth of water treeing through treatment of polyethylene modified with dialkyl disulfide and maleic anhydride.
However, these methods have still a disadvantage of not sufficiently inhibiting generation and growth of water trees.